Method of and apparatus for drawing glass articles.



R. S. PEASE. l METHOD of AND AP Tus Foa DRA GLASS ARTICLES. APPL 0NFILED NOV. l.

Patented Apr. 25, 1916.

3 SHEETS*SHEET Il ll R. ls. PEASE.

' METHOD 0F AND APPARATUS FOR DRAWING GLASS ARTICLES.

` APPLICATION FILED NOV- 9.1911.

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Patented Apr. 25, 1916.

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APPLICATION FILED NOV.9, 191|.

Patented Apr. 25, 1916.

3 SHEETS-SHEET 3.

WITNESSES ROGER S. PEASE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR. TOPITTSBURGH PLATE GLASS COMPANY, OF PITTSBURGH, PENNSYLVANIA, ACORPORATION OF PENNSYL- VANIA. v

METHOD OF AND APPARATUS FOR DRAWING GLASS ARTICLES.

Application led November 9, 1911.

To all whom t may concern:

Be it known that I, ROGER S. IEAsE, a citizen of the United States,residing at Pit-tsburgh, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inMethods of and Apparatus for Drawing Glass Articles, of which thefollowing is a specification.

My invention has reference to a method of and apparatus for drawingglass articles from a body of molten glass, and it relates particularlyto the drawing of glass cylinders for the making of window glass and thelike. Among the chief objects of my invention are: the provision of animproved method of drawing glass whereby the article is drawn from thepurest and best portions of the molten glass, thus reducing to a minimumbreakage from imperfections arising from a poor quality of glass due tothe presence of surface glass or other extraneous substance; and theprovision of improved apparatus for removing surface glass or extraneoussubstances from that portion of the glass from which the drawing is tobe done. These, together with such other objects as may hereinafterappear or are incidental to my invention I attain by means of aconstruction illustrated in preferred form in the accompanying drawings.

Of the drawings, Figure 1 is a longitudinal section through a dog houseand portion of the glass tank of the usual glass furnace construction.Figure 2 is section similar to that of Figure 1 showing the parts indifferent position; Fig. 3 is a section on the line III-III of Fig. 1just previous to the drawing of a. cylinder; and Fig. 4i is a plan of adetail of my invention. The steps employed in carrying out my improvedmethod of drawing glass are clearly indicated in the drawings, and forconvenience the apparatus will therefore be first described.

Referring particularly to Figure 1, I have .diagrammatically indicatedthe usual glass tank 1 communicating with the dog house 2, from whichthe glass is to be drawn. The molten glass in the tank and dog house isindicated by the numeral 3. The top wall or roof 4 of the dog house isprovided with the port or opening 5 to permit the passage of the bait 6and the cylinder being drawn thereby. Immediately beneath the portopening 5 is a dish-shaped drawing ring 7 Specification of LettersPatent.

Amolten glass is in its purest condition.

Patented Apr. 25, 1I 91d.

serial No. 659,353.

provided with upstanding projections or which is composed of tire clayor other refractory material of less density than the glass so that itwill float thereon. The drawing ring is composed of similar material.This plate, hereinafter to be termed a skimmer is manipulated by meansof the hooked rod 11. The bait (3 is provided with the. usual blow pipe12 and is lowered and elevated by any desired form of drawing mechanism.The surface of the glass is heated by a series of jets of the usualtype, one of which is diagrammatically illustrated at 13. When not inuse the rod 11 can be supported at its inner end on the bar 11 mountedlin the wall of the dog-house.

The operation of the apparatus is as follows: When a cylinder is to bedrawn, the drawing ring 7 is depressed by placing weights 14C in theopenings 14 in the plungers 8-8 until the entire ring is submerged belowthe level of the body of the glass, as indicated in Fig. 1. The skimmer1() is then moved across the submerged drawing rin by means of thehandle or rod 11 and left in a position a little to one side of thatindicated in dotted lines in Fig. l. In moving the skimmer across thedrawing ring, all of the surface glass remaining above the drawj ingring from previous drawing operations together with any ioatingextraneous substance which may be detrimental to successful drawing willbe carried toone side by the skimmer. The drawing ring is then permittedto rise and assume its normal floating position by lifting the weights14. This operation leaves a portion of glass remaining in the drawingring from which all extraneous substances have been removed, and as thedrawing operation continues the glass is fed through the opening in thebot-tom of the ring from the deeper portion of the glass in the doghouse, at which point the The edges of the ring which project above thelevel of the glass will prevent the impurities from linding their way into the drawing ring. It is well known in glass manufacture GU jacent thedrawing ring is a plate or disk 10 that all impurities and extraneoussubstances rise to the surface of the glass and that the glass is purestbelow the surface and it will be obvious that by this arrangement theliability of any imperfection in the cylinder being drawn arising from apoor quality of glass will be reduced to a minimum, as will thebreakages and loss which are a consequence thereof. After completion ofthe drawing operation the drawing ring is again submerged and theoperation is repeated.

As will be evident from the description of the apparatus and itsoperation above given, my improved method of drawing glass articlescomprises the following steps: the submersion of the drawing ring, theremoval of all surface glass and extraneous substances in the glassabove the drawing ring by moving the skimmer across the submergeddrawing ring, the elevation of the vdrawing ring so that the maincommunication with the interior of the ring will be had through theopening in the bottom thereof and then the drawing of the glass by meansof a bait in the usual manner.

In Figure 4 I have shown a plan view of the skimmer plate. As hereshown, the plate is cut away in its central portion and has its outeredges formed on a concave curve to facilitate the skimming operation,this shape serving to entrap the impurities and carry them along.

It will be obvious to thoseskilled in the art that the particular meanswhich I have shown for preparing the surface of the glass for anotherdrawing need not necessarily be employed and that even where the glassis prepared by remelting the surface, there are advantages in submergingthe drawing ring while the re-preparation is taking place. Thesubmergence-for v examplewill better expose the surface to the heataction if the remnant from the last drawing is' to be re-melted.

It is also to be noted that by the peculiar formation of ring employed,an action will be obtained in which the raising of the ring will itselftend to cause an outward flow of the surface glass above the ring, dueto the restricted aperture in the bottom of the ring and in this mannerthe ring is-by its being raised and lowered-made in a sense selfskimming.

Having thus described my invention and illustrated its use, what I claimas new and desire to secure by Letters Patent is the following:

1. The herein described process of drawing glass cylinders from adrawing ring floating on a body of molten glass which consists insubmerging the drawing ring below the level of the body of glass fromwhich the cylinder is to be drawn, in skimming off the portion of glassimmediately above the submerged drawing ring, then in raising thedrawing ring until a portion thereof projects above the level of thebody of glass, and 1n drawing the cylinder from 4the glass within thedrawing ring.

2. The herein described process of drawing glass cylinders from adrawing ring floating on a body of molten glass which consists insubmerging the normally floating drawing ring below the level of themolten glass, then in skimming off the glass immediately above thedrawing ring, then in permitting the drawing ring to assume its normalfloating level, and in drawing the cylinder from the glass within thedrawing r1ng.

3. In apparatus for drawing glass articles from a body of molten glass,the combination of a drawing ring, means for temporarily submerging thedrawing ring below the level of the-body of glass, a skimming means forskimming off the glass above the submerged drawing ring, and a bait fordrawing the article.

4. In apparatus for drawing glass articles from a body of molten glass,the combination of a drawing ring, means for tem` porarily submergingthe drawing ring below the level of the body of glass, a plate forskimming off the glass above the submerged drawing ring, and a bait fordrawing the article.

5. In apparatus for drawing glass articles from a body of molten glass,the combination of a normally floating drawing ring, means fortemporarily submerging the drawing ring below the level of the body ofglass, a normally floating member for skimming off the glass above thedrawing ring, means for moving said member across the submerged drawingring, and means for drawing a glass article from the drawing ring.

6. In apparatus for drawing glass articles from a body of molten glass,the combination of a normally floating drawing ring, means fortemporarily, submerging the drawing ring below the level of the body ofglass, guide means for maintaining the ring in position as it is beinglowered and raised, means for skimming ofl the glass above the drawingring when it is submerged, and means for drawing a glass article fromthe drawing ring.

7. In apparatus for drawing glass articles from a body of molten glass,in a tank or furnace, the combination of a normally floating drawingring provided with a plurality of projections, guide-ways in the furnacewall through which the projections slide freely, means for temporarilysubmerging the drawing ring below the level of the body of glass, askimmer for skimming off the glass above the drawing ring when it issubmerged and adapted to pass over the drawing ring between the projecaglass article from the glass in the ring l0 while suoli ring is 1n itsraised position, and

repeating the foregoing operations in the drawing of successivearticles.

In testimony whereof I have hereunto signed my name in the presence oftwo subscribed witnesses.

ROGER S. PEASE.

lVitiiesses Lnirrm A. MYERS, DOERING BELLINGER.

